2004 ISUZU TF SERIES torque

7A2-132 DIAGNOSIS (JR405E)
No. G3: Creep Force is small

Description:

Vehicle does not move though a run range is selected on a flat road during the idling.

Diagnosis Hints:

When the creep force is small in all ranges, low engine output is considered. Another possible cause is slip of
clutch. If the creep is normal only in the R range, operation of the fail-safe function due to a trouble in the electrical
system is considered.

Possible Cause:

Slip of clutch (low clutch).
If slip of clutch is caused, a DTC (gear ratio error) is stored.

Low engine output (low idling speed, out of injection timing, lowered compression pressure, etc.).

Shortage or faulty quality of ATF.

Disconnection or short circuit of solenoid valve output.

Clogged oil passage of solenoid valve output.

Faulty ground return line in AT assembly.
If the ground return line earth is faulty, clutch pressure may decrease causing slip of the clutch.

Trouble in the torque converter system (faulty operation).

Step Action Yes No
1 Gear ratio trouble diagnosis.
Travel in the following sequence for about 7 seconds or
more in each range: Start in the L range (1st) to 2 range
(2nd) to 3 range (3rd) to D range (4th) (to detect the gear
ratio trouble exactly, this process should be carried out)
Go to Step 2 Go to Step 2
2 Are any DTCs stored?
Go to DTC Chart Go to Step 3
3 Are the quantity, contamination and smell normal? If the ATF level is low,
replenish up to the
specified level.

Go to Step 4
If ATF is extremely
black and
contaminated and
smells burnt, slip of the
clutch is supposed.
Overhaul the AT unit.
4 Are the idling speed and other engine system normal?
Go to Step 5
Repair the defect or
replace.
5 Is the stall revolution normal in D, 3, 2 and L range? Refer
the STALL TEST section in this manual.
Go to Step 6
Repair the defect or
replace.
6 Is the line pressure normal? Refer the LINE PRESSURE
TEST section in this manual. Trouble in the AT
assembly or control
valve.
Repair the defect or
replace.

DIAGNOSIS (JR405E) 7A2-133
No. G4: Large Noise During Idling with the Vehicle in Stop State

Description:

The transmission is noisy during the idling speed in all ranges.

Diagnosis Hints:

Causes such as solenoid operating sound or faulty oil pump are considered.

Distinguishing to some extent is possible by stopping the solenoid operation temporarily, checking the correlation
for the former case and, changing the line pressure and confirming the correlation with noise.

As a matter of course, noise may be generated around the engine, for instance, other than the AT and should be
checked carefully.
Note:
When the noise is generated only at the time of gear shift, it may be the sound of flowing ATF or gear
noise. If the sound varies depending on the gear speed to be shifted, it may be the gear noise generated
from the planetary gear and its related components. If the sound varies depending on the vehicle
speed, it may be the gear noise of the output system, and if varying depending on the engine speed, it
may be the gear noise of the input system or faulty torque converter.
In either case, sound may be "noise" depending on the origin and resonance object. When the object
generating the sound (resonance object) and the sound source (vibration source) are different,
investigation of the cause may be difficult.





No. H1: Judder Occurs at the Lock-up

Diagnosis Hints:

The vehicle body judders at lock-up.

Diagnosis Hints:

Slip due to burning of the lockup piston or insufficient fastening due to dropped working pressure are considered.
Trouble diagnosis flow is basically the same as "No. I1: No lock-up".
Note:
When the lock-up piston has burnt, foreign material mixed in the oil cooler is considered. In such a
case, inspect the oil cooler circuit for clogging of the oil cooler.





No. H2: Large Lock-up Shock
No. H3: Lock-up Point is High or Low

Description:

Large shock is felt at lock-up.

Lock-up point is excessive high or low.

Diagnosis Hints:

Out of properties of input sensor or faulty lock-up piston pressure system are considered.

Trouble diagnosis flow is basically the same as "No. I1: No lock-up".

7A2-136 DIAGNOSIS (JR405E)
No. J1: Oil Leaks from Breather

Description:

Oil leaks from breather.

Possible Cause:

ATF quantity is excessively.




No. J2: Oil Leaks Between Engine and Converter Housing
No. J3: Oil Leaks Between Main Case and Converter Housing
No. J4: Oil Leaks Between Main Case and Rear Housing
No. J5: Oil Leaks from Oil Pan
No. J6: Oil Leaks from Manual Shaft Oil Seal
No. J7: Oil Leaks from Oil Cooler Pipe Joint

Description:

Oil leaks between engine and converter housing.

Oil leaks between converter housing and main case.

Oil leaks between main case and rear housing.

Oil leaks from oil pan.

Oil leaks from manual shaft oil seal.

Oil leaks from oil cooler pipe joint.

Possible Cause:

Faulty oil seal or sealing of contact surface is considered.

No. Z1: Transmission Overheat

Description:

You smell the transmission burning.

The transmission smokes.

Possible Cause:

Slip of clutch.
If slip of clutch is caused, a DTC (gear ratio error) is stored.

Clogged oil cooler (foreign substance mixed)

ATF stirred excessively (too much ATF).

Faulty torque converter operating pressure.

Faulty lock-up piston.

7A2-140 DIAGNOSIS (JR405E)
STALL TEST
CAUTION:
Because A/T may break down, do not perform the stall test continuously.

Procedure
1. Chock the four wheels.
2. Warm up the engine.
3. Apply the parking brake.
4. Step on the foot brake fully.
5. Set the select lever to either D, 3, 2, L or R range.
6. Step on the accelerator pedal fully.
7. When the engine speed becomes constant, record tha
t
value quickly.

Stall Speed
Standard: 2600±150 rpm

Evaluation
1. If the stall speed is higher than standard value in all
ranges.

Low line pressure.

Abraded oil pump.

Faulty operation of low clutch.

Adjustment error of or faulty inhibitor switch.


ATF leaking from oil pump, control valve, or
transmission case.

Fixed pressure regulator valve and pilot valve.
2. If the stall speed is higher than standard value in D, 3, 2
and L ranges.

Slip of low clutch.

Slip of low one-way clutch.
3. If the stall speed is higher than standard value in
R
range.

Slip of low & reverse brake.

Slip of reverse clutch.
4. If the stall speed is lower than standard value in all
ranges.

Slip of one-way clutch (in torque converter).

Faulty engine.

DIAGNOSIS (JR405E) 7A2-141
LINE PRESSURE TEST
Procedure
1. Chock the four wheels.
2. Remove the test plug of the transmission case and fit the oil
pressure gauge.
3. Warm up the engine.
4. Apply the parking brake.
5. Step on the foot brake fully.
6.Set the select lever to either D, 3, 2, L or R range.
7. Record the oil pressure at idling.
8. When stepping over the accelerator pedal fully and the
engine speed becomes constant, record the oil pressure
quickly.

Line Pressure
Standard:
Engine Line Pressure (Kpa)
Speed D, 3, 2 or L Range R Range
Idling 350 - 480 450 - 650
Stall 1,050 - 1,250 1.400 - 1,630

Evaluation
1. If the line pressure is lower than standard value at
idling in all ranges.

Abraded oil pump.

Faulty operation of each solenoid.

Sticking of pressure regulator valve or pilot valve.

Fatigued pressure regulator valve or pilot valve spring.


ATF leaking from oil strainer, oil pump, pressure
regulator valve, torque converter relief valve or pressure
relief valve.
2. If the line pressure is lower than standard value at
idling in D, 3, 2 and L ranges.

ATF leaking from low clutch hydraulic circuit.
3. If the line pressure is lower than standard value at
idling in R range.

ATF leaking from reverse hydraulic circuit.

ATF leaking from low and reverse brake hydraulic
circuit.

7A2-146 DIAGNOSIS (JR405E)

5. If there is no reverse.

Reverse clutch malfunction.

Reverse clutch hydraulic circuit failed.

Low & reverse brake hydraulic circuit failed.

Low & reverse brake duty solenoid stick.
Refer to symptom diagnosis "No. A2: Vehicle Dose Not
Run in R Range" or DTC section "Low & Reverse
Brake Duty Solenoid Failure".
6. If there is no parking.

Parking pawl malfunction.
Refer to symptom diagnosis "No. G1: Vehicle Moves in
P Range or Parking Gear in Not Disengaged othe
r
than P Range".

NOTE:
The check for the cause of abnormal noise and vibration
must be made with extreme care as it could also be due to
loss of balance in propeller shaft, differential, the torque
converter, etc. Or insufficient bending, rigidity, etc. in the
powertran.

ON-VEHICLE SERVICE (JR405E) 7A3-3
Cold Level
The vehicle must not have been driven so that the
temperature reaches around 20
C (68
F) before the
cold level check is made.
1. Park the vehicle on a level surface.
2. Apply the parking brake firmly.
3. Start the engine and allow it to warm up.
The engine coolant temperature gauge needle
should be midway between the “C” mark and “H”
mark.
4. Let the engine run at idle.
Move the select lever slowly through all the gea
r
ranges.
Stop in each range just long enough for the
transmission to engage.
5. Return the select lever either “P” or “N”.
6. Remove the ATF level dipstick.
7. Wipe the dipstick clean with a paper towel.
8. Reinsert the dipstick and wait several seconds.

9. Remove the dipstick.
The ATF level should be inside the “C”range on the
dipstick.
If the ATF level is below the “C” range, ATF must be
added.
242R300002


ATF CHANGE
1. Start the engine and allow it to idle until the ATF
reaches a temperature of 40-50
C
2. Park the vehicle on level ground and block the
wheels.
3. Stop the engine.
4. Raise vehicle and support with suitable safety
stands.
5. Remove the drain plug from the oil pan and drain the
ATF (approximately 6 liters).
6. Remove the oil pan.
7. Inspect the oil pan (details written below).
8. Install the oil pan.
Note:
Use new gasket. Clean the oil pan and magnet.
Oil pan bolt torque : 8 Nm (69 lbin)
9. Replace the gasket and install the drain plug.
Drain plug torque : 35 Nm (26 lbft)
Note:
Do not reuse old washer (gasket).
Clean the drain plug (especially the threaded section).
10. Pour about 5 liters of new ATF. Then, add more ATF
carefully as necessary using the dipstick.
Refer to “ATF LEVEL” previously in this section.
Note:
Keep the engine idle (do not stop it) during the oil level
adjustment.
11. Remove the safety stands and wheel blocks. Inspect
1. Check the drain plug tip for adhesion of foreign
substances.
2. Check the drained ATF for color, smell and inclusion
of foreign substances.
3. Check the oil pan bottom and magnet for adhesion o
f
foreign substances.
If a problem is discovered during those checks, the
Automatic transmission must be overhauled.
Note:
The torque converter and the oil strainer need replaced
with new ones if the drained ATF contains large
amounts of metallic or facing flakes.
In addition, flush the ATF cooler circuit

7A3-6 ON-VEHICLE SERVICE (JR405E)
INHIBITOR SWITCH
The inhibitor switch is attached to the right side of the
transmission.

Inspect
1. Block the wheels.
2. Disconnect the negative battery cable.
3. Disconnect the harness connectors.
4. Use a ohmmeter to check the inhibitor switch
continuity between the following terminals as shown
in figure.
5. Place the select lever in the “N” range.
249R300001
6. Move the select lever to either side.
Check the inhibitor switch continuity between the
terminals shown in Step (4).
The continuity readings should remain fairly steady
as the select lever is moved.
If there is no continuity or the continuity is
intermittent, the inhibitor switch must be adjusted.

Adjust
1. Disconnect the shift calbe from the lever.
2. Loosen the inhibitor switch bolts.
3. Use the inhibitor switch set plate to align the neutral
holes (manual shaft and inhibitor switch).
Turn the inhibitor switch to adjust it.
Inibitor switch set plate: 5-8840-2763-0
Note:
Inhibitor switch adjustment is very important.
If the inibitor switch is not correctly adjusted, the
automatic transmission will not function normally.



4. Tighten the 2 inhibitor switch bolts to the specified
touque.
Torque: 5.5 N·m (48 lb·in)
47INH-SW01
5. Connect the shift cable to the lever.
6. Connect the harness connector.

Remove or Disconnect
1. Remove the cable bracket (1) from the transmission.
2. Disconnect the shift cable (2) from the lever (3).
3. Disconnect the harness connectors.
4. Remove the inhibitor switch bolts.
5. Remove the inhibitor switch (4) from the
transmission.

238R300001